Ingame there is a Wood Plate that can be salvaged. However there is also a "Wooden Plate" that looks identical and can´t be salvaged. Simply typo and it should all be Wood Plate? Or a bug that both are distinct but the wooden ones should be salvageable, too?
if you try placing them as deco you'll see they are not the same plate. one not being salvageable would only be a bug if its description says it IS salvageable.
Basically *many* of the various deco items were set to be salvaged, and then some are still not set to salvage. You can identify the ones that are set to salvage, by reading it's description. If the items does NOT have the description it can be salvaged, those are the ones not set up to be salvaged yet.